[dv657172]

Removed rear slicks to replace for new season as existing ones quite old despite only having about 40 passes on them.

DS tire has rubbed the inner fender (shiny spots in 1st pic) and even the frame in front of the tire. While I assume its ocurring on the launch and due to running too low of tire pressure, I would have expected the issue to show on the PS but there is no rub marks on that side.

65 GTO dedicated drag car (estimate 11.90 area in qtr mile, 7.60 actual 1/8 mile time)
3500 lb with driver
Moser 9" rear, boxed lower control arms, adjustable uppers, 70/30 shocks, stock springs, still running an air bag on PS only at 15 lbs
Hoosier 10" x 26 drag slicks, bias ply at 14 psi
Transbrake launch at 4,000 rpm

Is it just a tire pressure issue? If so why on the DS and not PS? Lack of preload on DS?

Car sticks good (1.65 60 ft) but tires do crinkle quite a bit

Thanks for any thoughts on why DS and not PS and any recommendations
DV

[Skip Fix]

Rear end not centered? specially with a non factory rear you add more variables. But most Second gen F bodies the rear is not centered i think my 81 TA it is 3/4" out on passenger side.
A different wheel offset or a thin spacer could get it OK.

[ErikW]

Just use a thin spacer

[turbo69bird]

Have you taken the springs out and lowered the car into the tires? I wouldn’t worry about it rubbing on a flat but I saw someone crash fatally from a cut tire in testing so it’s not anything to just shrug off if there’s anything sharp it could contact.

I had a diagonal link break after street use at the track and luckily it didn’t cut a tire but it did groove it was no joke trying to stop that thing at 150 mph w the diagonal
Link loose.

[Dragncar]

My old Hoosier 12" slicks used to rub like that.
Went to MT 10.5" drag radials and never looked back. No rubbing, very stable.
Never thought I would get a better 60 foot, but I did.

[dv657172]

Thanks for the replies!

Haven't changed the springs from when I bought the car but I am sure they are not optimal for racing front or back. Not yet....

Will try a thin spacer and see if that works along with seeing if car will take a bit more tire pressure.

Thought it was curious that it was only occurring on DS when I would think biggest hit is on PS but maybe preload on PS is the difference.

Dragncar - will keep the MTs in mind next time around

[hojs69]

Does the car leave straight? Could it be dipping the chassis on the DS Rear down, PS front-end up, twisting / rolling the frame so it it closer to the top side of the tire on the inner DS?

The rubbing looks to be relatively subtle in nature. Not consistent, like always, or you would probably feel it. Maybe occurring just on the leave, or perhaps over driveways, ramps, incline, etc....

[turbo69bird]

Those cars I believe usually squat hard on the PS and lift the right side - to the point they look as though they’d roll over w out air bags. I’d say someone just offset it incorrectly or something is bent. But a small spacer should cure it

[dv657172]

Car does leave straight and looks level from behind on launch with 15 lbs in air bag on PS. Will try and measure if housing is centered under the car.

[Gary H]

Mine rub when I turn corners. That may be where you're getting the shiny spot from. If not, use a thing spacer on that side.

[dv657172]

Thanks Gary H, I had not thought of that as a possible cause

[dv657172]

3/16" spacer on DS appears to have fixed the issues. New slicks, no rub marks!

Thanks for all the help
DV